1. Field of Invention
The present invention relates to a method and apparatus for aligning fibrous components of materials. More particularly the present invention relates to a method and apparatus for applying compression waves to temporarily molten or liquified materials to effect the substantially parallel alignment of fibrous components within the materials.
2. Description of the Prior Art
Many composite materials are available which comprise fibrous elements or "whiskers" which are randomly distributed throughout a base material. Common fabrication materials such as graphite composites and fiberglass composites are examples of such materials. Fibers and whiskers are typically used in such composite materials in order to take advantage of the relatively high tensile strength of the fibrous elements vis-a-vis the base materials. By randomly distributing whiskers throughout a relatively low strength base material the yield strength of the composite becomes greater than that of the base material alone, due primarily to the fact that for any force applied to the composite material, some portion of the (relatively high tensile strength) whiskers will always be aligned parallel to the direction of the applied force. Typically the macroscopic properties (eg. tensile strength, yield strength, modulus of elasticity, etc.) of such composite materials are independent of the physical orientation of the materials or the direction of application of external forces upon the materials. Thus, such materials are inherently no stronger in one direction than they are in any other direction.
Certain structures (for example cables, belts, columns, beams, etc.) are commonly subjected to loads which are predominantly directed only along, or parallel to, particular axes of the respective structures. In the case of cables, for example, under normal conditions most of the stresses are usually applied only axially along the cables. Similarly, belts are typically exposed to relatively higher stresses parallel to their longitudinal axis than in other directions. It is frequently desirable, therefore, to construct such structures of materials in which their tensile and/or compressive strength parallel to one axis of the structure is substantially greater than its tensile and/or compressive strength in other directions.
A prior method of producing materials which are inherently stronger parallel to one axis than in other directions comprises aligning a plurality of elongated wires, cables, filaments or the like parallel to a common axis and embedding them within a base material. The resulting composite material is typically stronger parallel to the axes of the embedded materials than in other directions. Concrete structures with aligned and embedded reinforcing bars, and composite plastics having embedded woven glass fabrics, are examples of such structural materials whose tensile strength, compressive strength, and modulus of elasticity all vary depending upon the direction of the applied loads.
Prior methods of fabricating composite materials comprising aligned filaments, wires, rods and similar embedded elements typically require the use relatively long embedded elements because of the necessity to manually or mechanically handle and place the embedded elements in a fixed orientation relative to each other and to the base material. However, because of the difficulty, (indeed the near practical impossibility), of manually or mechanically handling and placing microscopic fibers, filaments, or chains, and the difficulty in handling and placing macroscopic whiskers and other small loose fibers, prior composite materials typically do not comprise such elements in aligned arrays. Thus, whenever such small fibrous elements are used in prior composite materials they are typically randomly distributed and randomly oriented; and, being randomly distributed and randomly oriented, such small fibrous elements provide the prior composite materials with no structural properties which are dependent upon the direction of application of applied external loads.